I'm upset about the new kitten. Should I be?

Hello George,
Whicky is a friend of mine and he advised me I to speak to you about my problem.The problem is my new kitten brother, Alfie. He arrived last weekend (from cat rescue aged 12 weeks) and Mom is trying to settle him in with me. I am 8 months old and a bit of a spoilt only boy until now.I've been a bit hissy and growly - and because I am so much bigger and stronger than Alfie, Mom is nervous about leaving us unattended. She introduced us behind a glass door (one either side) and I was very hissy & growly!Then gradually over the weekend she fed us at the same time (one each side of the door) and now I am comfortable near my little brother. BUT Mom closely supervises and I show interest and sniff - and then give a hefty swipe. My claws are usually in ... but sometimes I forget myself.Mom is scared that if she puts Alfie down that I might attack and hurt Alfie. I don't mean to be like this ... I can't help myself.Mom is giving me lots of reassurance but she wonders if you could advise further. Is there anyhting else she should be doing, or not doing? Thank you.
Love Milo

Dear Milo,
Unlike many of us, you seem to have a sensible human. You must have educated her well in the ways of cats. Or perhaps she was already socialised to cats when she was a human kitten. Either way she is being patient and kind. (Not very common among in this pathetic species. We can wait for hours at mouseholes. They want it all now.)
The difficulty for our humans is that they are primarily social animals but we are not. We don't live in packs like dogs do (which is one reason why they fit into human life so well). We weren't designed to do cooperative hunting, like both wolves (dogs) and humans. We hunt alone. We go out alone and we kill mice. Mice are not big enough to share so we don't share our food with others - unless we are mother cats bringing back food for kittens.
That's not to say that we cats are all loners. Some of us are. Some of us will always be unhappy sharing a house. But, if we were in the wild, many of us would live in colonies of related females. The toms would come and go but females would live closely together. The sisters and neices might even help each other raise kittens, share nursing duties, and baby sit.
Where does that leave us house cats? Well humans like more than one cat and they will often bring home a new cat. For us cats this is upsetting. This new cat will not be a relative. It will smell different to us and we identify friends and foe by scent. Any cat that isn't familiar is a foe until it becomes familiar. And even if it is a kitten, well, some of us don't care for kittens much. This all adds up to a period of between 3 to 6 months while we come to terms with the new arrival
What we need is time to accept the change. Next we need the smell to come right. We need the new cat to start smelling of our family - ie smelling of us, and our humans. Swapping bedding form one cat bed to another, installing Feliway, and getting the human to stroke first one cat and then the other will help. We like a nice mixed scent that all the family share. Feliway is always soothing.
A crate for the kitten to be in - large enough for bedding, food and litter tray - is a help. Means you can't swipe at him but you can go close and take a good look. (Crates are useful for sick cats too or for if you take your cat travelling or on visits. I love my crate.).
Finally we need space and resources. We will probably never want to get too close to another unrelated cat. We will live happily in the same house while making sure we are about three metres away at all times. So ask her to help you and the new kitten to avoid each other. That is what we cats do to make social life bearable. You need at least one litter box per cat and at least two different litter locations. It will also help if you are not forced to eat side by side. So two feeding locations will help too.
Keeping our distance is how we cats cope. Your human is being helpful in this. She's obviously a relatively enlightened individual of an otherwise dumb species. She seems to realise that cats are not human - some humans never do.
George.
PS. She's written yet another book under my guidance. See above. Order it for Xmas at www.amazon.co.uk